WO2002101040A1

WO2002101040A1 - Human-type anti-blood coagulation factor viii antibody

Info

Publication number: WO2002101040A1
Application number: PCT/JP2002/005783
Authority: WO
Inventors: Toshihiro Nakashima; Masato Yuguchi
Original assignee: Juridical Foundation The Chemo-Sero-Therapeutic Research Institute
Priority date: 2001-06-12
Filing date: 2002-06-11
Publication date: 2002-12-19
Also published as: AU2002313194B9; EP1396539A1; JP4205576B2; US20040120951A1; JPWO2002101040A1; DK1396539T3; EP1396539B1; ES2316574T3; CA2418808A1; DE60230037D1; US7214785B2; KR20030029128A; ATE415472T1; PT1396539E; KR100925348B1; AU2002313194B8; EP1396539A4; AU2002313194B2

Abstract

A human-type anti-blood coagulation factor VIII (hereinafter referred to as FVIII) which binds to human FVIII and specifically inhibits the blood coagulation activity thereof, and its antibody fragment. An scFv display phage library, which has been constructed by using scFv DNA on the basis of random combinations of the VH chain gene and VL chain gene of immunoglobulin originating in lymphocytes of a patient with hemophilia A, is reacted with FVIII having been immobilized on a solid phase via an anti-FVIII monoclonal antibody. Then scFv clones capable of binding to FVIII are screened to thereby clarify antibody VH chain and VL chain specific to FVIII.

Description

Specification

Human anticoagulant factor VIII antibody

Technical field

The present invention relates to the provision of a humanized anti-FVIII inhibitor antibody and an antibody fragment that bind to human blood coagulation factor VIII (hereinafter sometimes referred to as FVIII) and specifically inhibit its blood coagulation activity.

Background art

Hemophilia A is a hereditary disease that causes bleeding in the internal organs and joints as a result of weakened blood coagulation due to abnormal or defective FVIII. FVIII replacement therapy is used to treat patients with hemophilia A, but approximately 10% (8

~ 15 ° / ₀ ), the appearance of antibodies against FVIII is observed. This antibody, called an anti-FVIII inhibitor antibody, disables clotting factor replacement therapy and makes hemostatic management of hemophiliacs significantly more difficult.

Elucidation of the properties and production mechanism of these anti-FVIII inhibitor antibodies would enable inhibitory antibody production and suppression. Studies using anti-FVIII inhibitor antibody (polyclonal antibody) and mouse anti-FVIII inhibitor antibody (mouse monoclonal antibody) purified from serum of hemophilia patients to whom anti-FVIII inhibitor antibody has appeared so far have gained much knowledge. However, there have been few reports of closing of patient-derived anti-FVIII inhibitor antibodies. On the other hand, epidemiological studies show that haemophilia patients have a lower incidence of arteriosclerosis such as myocardial infarction (particularly, a significantly lower incidence of fatal myocardial infarction) (Br. J. Haeraotol. 1990, 75, 525-530, Lancet 1995, 345 (8943) 152-155), Increased plasma FVIII is a risk factor for arterial infarction and arteriosclerosis (Semin. Hematol. 1997, 34, 171-187, Thromb. Res. 1997, 84, 359-362), and if it is possible to maintain a low coagulation state using an anti-FVIII inhibitor antibody, etc., it will contribute to the prevention and treatment of arterial infarction and arteriosclerosis. Be expected. In particular, an anti-FVIII antibody capable of specifically recognizing activated FVIII dissociated from von Willebrand factor (hereinafter sometimes referred to as vWF) is normally associated with FVIII present in the blood in a state bound to vWF. Long clearance in the blood due to no complex formation, low coagulation for a long time with a single administration It can be used as an excellent antithrombotic treatment with less tendency to bleeding and other side effects.

Many facilities, including us, have already attempted to produce mouse monoclonal antibodies, and many monoclonal antibodies against FVIII have been produced. Some of them have been shown to inhibit FVIII activity and behave as anti-FVIII inhibitor antibodies. Many results have been obtained using these mouse monoclonal antibodies, such as analysis of the FVIII activity inhibition region.

Disclosure of the invention

(Technical problems to be solved by the invention)

The production of fully human anti-FVIII inhibitor antibodies has been achieved by a number of facilities.

Although it has been studied for more than 10 years using the hybridoma method (human mouse, human hybridoma method) and EB transform method using lymphocytes from patients with FVIII inhibitor antibody, the difficulties have been clarified. Was.

In 1989, Marc G. Jacquemin et al. Reported the first use of the EB transform method (Blood, 92 (2), 1998, 496-506). The B O 2 C 11 antibody they established inhibited the binding of FVIII to vWF and phospholipids,

It is thought that it recognizes and recognizes the two domains, and its antibody binds to VH derived from the DP5 fragment.

VL derived from Vκ3. They also anti-F against the C1 domain in a similar manner.

We also succeeded in establishing a VIII inhibitor antibody-producing clone and reported that the antibody was derived from DP64 and V / C3 (Blood, 95, 2000, 156-163). Currently, such human-derived anti-FVIII inhibitor antibody-producing clones have been established by the hybridoma method (human mouse, human human hybridoma method) and the EB transform method.

There is only a gnore such as Marc G. Jacquemin.

On the other hand, the phage antibody method (J. Mol. Biol, 222, 581-597, 1991) reported by JD Marks et al., Compared to the conventional hybridoma method and the EB transform method, is an antibody repertoire derived from patient lymphocytes. This has the advantage of being able to screen many clones in a short time. In recent years, approaches for inhibitor antibody isolation by the phage antibody method have been attempted. At the International Society for Thrombosis and Hemostasis (Israel) (1995, ISTH) in June 1995, WH Ouehand et al. Cloning of human anti-coagulation factor VIII single-chain antibody (scFv) from a human phage antibody library and a synthetic human phage antibody library was reported in June, 1997. At the Society of Thrombosis and Hemostasis, J. Davis and colleagues reported that human VH was derived from a hemophilia patient and VL was derived from a human phage antibody library derived from a healthy human and a human anticoagulant factor VIII single-chain antibody (scFv). Reported that they had crawled. However, these construct human or phage antibody libraries by synthesis or semi-synthesis, and neither VH nor VL is completely derived from hemophilia patients. Furthermore, although the clones obtained in these reports have binding ability to FVIII by ELISA, they have not been confirmed to inhibit the coagulation activity of FVIII. In 2000, EN van den Brink and others constructed a phage antibody library in which the VL chain was derived from a normal human and the VH chain was derived from a patient with an inhibitor, and isolated four FVIII-reactive clones. An Den Brink Human antibodies with specificity for the C2 domain of factor VIII are derived from VH1 germline genes (two reported that two species are reactive with the C2 domain of FVIII and two with the A2 domain. Blood. 2000; 95: 558-563), Molecular analysis of human anti-factor VIII antibodies by

V gene phage display identifies a new epitope in the acidic region following the A2 domain (Blood. 2000; 96: 540-545)).

It has been reported that the C2 domain is involved in binding to vWF and phospholipids and is a major recognition region for many anti-FVIII inhibitor antibodies in patient blood (Healey, JF, et al. Residues Glu2181-Val2243 contain a major determinant of the inhibitory epitope in the C2 domain of human factor VIII, Blood, 1998, 92, 3701-3709).

In a study by van den Brink et al., an antibody fragment against the C2 domain was obtained, but the antibody fragment did not have FVIII inhibitory activity. Therefore, the isolation of human anti-FVIII antibody having inhibitory activity using the phage antibody method has not been successful yet and sufficient knowledge has not been obtained.

(How to solve it)

Conventionally, human anti-FVIII antibodies having inhibitory activity could not be separated using the phage antibody method because the VL chains of antibody fragments were derived from patients. It is presumed that there is no screening method and there is a problem with the screening method.

The present inventors have intensively studied and solved these problems, and as a result, have isolated a novel anti-FVIII inhibitor antibody having clear specificity and inhibitory activity against FVIII from patient lymphocytes using the phage antibody method. Succeeded and revealed the specific antibody VH and VL chains.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows an example of measurement of human FVIII by ELISA using a combination of an ELISA plate on which an anti-human FVIIIA2 mouse monoclonal antibody is immobilized and the obtained scFV clone.

FIG. 2 shows an example of measurement of test team FVIII using three types of anti-human FVIII purified scFV.

Fig. 3 shows the FVIII remaining using purified sc Fv by measuring the partially activated thromboplastin time (APTT) when using purified FVIII preparations containing FVIII without vWF and multimeric vWF in human FVIII. The evaluation results of the activity are shown.

BEST MODE FOR CARRYING OUT THE INVENTION

First, in order to obtain information on the variable (V) region of a human anti-FVIII inhibitor antibody, the present inventors used RT-PCR from peripheral blood B lymphocytes of a hemophilia A patient having an anti-FVIII inhibitor antibody. Amplified immunoglobulin heavy and light chain cDNAs, and combined them with linker DNA to produce single-chain FV (scFv) DNA by random combination of VH and VL chains from patient lymphocytes .

Incorporate the sc Fv DNA in phagemid vector pCANTAB5E, to prepare a sc Fv display phage library of 10 ⁷ clones or Ranaru hemophilia A patient-derived. This library was reacted with FVIII immobilized on a solid phase via an anti-FVIII monoclonal antibody, and an anti-FVIII-sc Fv display phage clone capable of binding to FVIII was screened.

The anti-FVIII monoclonal antibody is produced by a conventional method, and a mouse monoclonal antibody is used. The anti-FVIII monoclonal antibody is preferably an antibody that recognizes the conformation-dependent epitope of the A2 region of FVIII or the L chain of activated FVIII. Using such antibodies Thus, FVIII can be retained on the solid-phased carrier without significantly changing the three-dimensional structure. Thus, each of the anti-FVIII mouse monoclonal antibodies that recognize non-recognized Epitopu anti _FVin This screening system - so that the phage clones showed coloration of _S c FV are obtained.

Further, by labeling the monoclonal antibody with biotin and using avidin-immobilized magnetic particles as a solid phase, an anti-FVIII-scFV display phage clone capable of binding to human FVIII can be easily recovered.

The use of a biotinylated anti-FVIII mouse monoclonal antibody eliminates the need for purified FVIII and enables screening with a small amount of FVIII.

As a result of the screening, seven types of scFv clones having anti-FVIII binding ability were isolated, of which three inhibited FVIII clotting activity. The VH gene of the three clones obtained was derived from DP-5 (1-24) of VH1 family, and the VL gene was derived from DPK9 (012/02) of Vκ1 family. The VHs of the other four clones are derived from DP-88 or 4M28 of the VH1 family, and VL is DPK22, Vg,

It was derived from DPK9 and IGLV6S1, and was different from clones having inhibitory activity. The VH of the clone having FVIII clotting activity was derived from the DP-5 segment similar to that of Marc G. Jacquemin et al., But the sequence of CDR3 of VH was greatly different. Mutation of serine or threonine to glutamine in the CDR3 sequence of the VL chain of these clones almost eliminates the FVIII binding activity of these clones. We revealed that CDR3 of the VL chain plays an important role.

The nucleotide sequence and amino acid sequence of the VH chain and VL chain of the three clones (YK3.3.38, YK3.3.40, YK3.3.50) obtained are shown in the sequence listing. YK3.3.38 VH chain and VL chain are shown in SEQ ID NOS: 1-2 and SEQ ID NOS: 3-4, and YK3.3.40 VH chain and VL chain are shown in SEQ ID NOs: 5-6 and SEQ ID NOs: 7-8, YK3.3.50 Are shown in SEQ ID NOS: 9 to 10 and 11 to 12, respectively.

Further, in the sequences, the amino acid sequences of CDR1 to CDR3 of the VH chain and VL chain are shown in SEQ ID NOs: 13 to 18. The definitions of CDR 1, 2, and 3 are based on Kabat's (EA Kabat et al., Sequences of Proteins of Immunological Interest, 4th ed., US Department of Health and Human Services, Washington DC (1987)).

[VH chain]

CDR 1: Glu Leu Ser lie His

CDR 2: Gly Leu Asp Arg Glu Asp Gly Lys Xaa Val Ser Ala Gin Arg Phe Gin Gly (Xaa: Thr or Ala) <SEQ ID NO: 14>

CDR 3: Gly Val Ala Ser Asp Asp Asp Ala Phe Glu lie SEQ ID NO: 15> [VL chain]

CDR 1: Arg Ala Ser Gin Serlie Xal Xa2 Tyr Leu Asn (Xal: Ser or

Thr; Xa2: Ser or Arg) SEQ ID NO: 16>

CDR 2: Ala Ala Ser Ser Leu Gin Ser <SEQ ID NO: 17>

CDR 3: Gin Xal Ser Tyr Xa2 Thr Pro Xa3 Thr (Xal: Gin or His; Xa2: Ser or Thr; Xa3: Leu or lie) <SEQ ID NO: 18>

SEQ ID Nos. 1-2 and 3-4, 5-6 and 7-8, 9-10 and 11-

The nucleotide sequence and the amino acid sequence described in 12 correspond to the heavy chain (VH chain) and Ό ^ chain (VL chain) of the V region of a human anti-FVIII inhibitor antibody having an inhibitory activity on human FVIII clotting activity. Things.

The VH chain and Z or VL chain disclosed in the present invention are those obtained in the form of scFV using the phage antibody method, but in principle, the application is not limited to scFv. The complete VH and Z or VL chains are linked to the constant region of human immunoglobulin, or the combination of a part of the constant region of human immunoglobulin with Fa b, F ab 'or F (a b') ₂ , Further, other antibody fragments such as a single-chain antibody (scAb) in which scFv is linked to a constant portion of human immunoglobulin are also included in the applicable range.

The same applies to modified protein molecules in which a polymer modifier is bound to these antibody and antibody fragment protein molecules.

In addition, as a result of analyzing the properties of the antibody fragment obtained by the present invention, the FVIII epitope recognized by the FVIII was eliminated by treating the FVIII with SDS. Furthermore, FVIII bound to these antibody fragments could not bind to phospholipids or VWF. Therefore, these antibody fragments do not bind to FVI11 bound to vWF flowing in the blood, but only to FVI11 that has been dissociated from VWF and become activated. ing.

These antibody fragments compete with inhibitor antibodies from patient plasma. Therefore, it is presumed that these antibody fragments recognize the same epitope as the patient's inhibitory antibody and the structure-dependent epitope of the C2 domain, and have the same properties.

In addition, the FVIII inhibitory activity of these antibody fragments was very strong, between 6700 and 29100 Bethesdanite mg.

(Effective effect than conventional technology)

As described above, the humanized monoclonal antibody and antibody fragment molecule of the present invention can strongly inhibit the coagulation activity of FVIII and can be used as a drug for preventing and treating thrombosis. In particular, the humanized monoclonal antibody and antibody fragment molecule of the present invention do not recognize the FVIII-vWF complex, and can recognize and recognize only activated FVIII not bound to the von Vibrant factor. It is possible to react only with activated FVIII without reacting with the FVIII-vWF complex present in it.

This means that it has an extremely long half-life in blood and is expected to have excellent effects unlike other antithrombotic agents that are unlikely to cause side effects such as bleeding tendency, and it is an excellent new antithrombotic agent that can monitor its effects by APTT measurement etc. It is shown that it becomes.

In addition, the human monoclonal antibody and antibody fragment molecules of the present invention, due to their characteristics, reduce the level of active FVIII dissociated from vWF in blood by combining an anti-FVIII antibody that recognizes another epitope (antigenic determinant). It is possible to measure the immunological measurement method.

In addition, the complex of the present invention in which the human monoclonal antibody and the antibody fragment molecule are adsorbed with an immunoadsorbent comprising an immunologically inactive adsorbent can be used in many applications.

First of all, trace amounts of FVIII present in human plasma or serum It can be purified by take-mouth chromatography. Further, it can be used for purifying FVIII in a culture supernatant produced from a cultured cell transformed by a genetic recombination method.

Second, anti-idiotypic antibodies against the variable region of the present antibody are purified by immunoaffinity chromatography using human monoclonal antibodies and antibody fragment molecules in human plasma or serum or human immunoglobulin fractions or drug products. It becomes possible to do. This provides a new option for treating patients with an inhibitor antibody of similar properties to the present antibody.

That is, by continuously administering these anti-idiotype antibodies to the patient before or simultaneously with administration of the FVIII preparation, or by removing the inhibitor antibodies by immunoadsorption using the anti-idiotype antibodies, the anti-FVIII inhibitor antibody Activity can be suppressed. Currently, treatment of patients with inhibitors, especially in the case of severe bleeding or surgery, requires administration of large amounts of FVIII to neutralize the inhibitors present in the blood and reach a level of hemostasis. . It is known that this treatment leads to an increase in inhibitory antibodies, resulting in reduced hemostatic effect and a tendency to bleed. Anti-idiotype antibodies have low antigenicity because they are human antibodies, and have little risk of side effects because they are specific.

Further, instead of the protein A-immobilized column used for removing the inhibitor antibody, the use of such an anti-idiotype antibody-immobilized column makes it possible to specifically remove the inhibitor antibody.

Furthermore, a peptide at a variable site of the human monoclonal antibody and antibody fragment molecule of the present invention, in particular, a complementarity determining region (CDR) peptide or a polymer carrier modified with the peptide, is used to inhibit the inhibitor antibody. The present invention provides a novel tolerogenic drug that induces idiotype antibody production. Attempts have already been made to tolerate patients with inhibitors using FVIII products. This is a method in which the FVIII preparation is repeatedly administered periodically during non-bleeding to reduce or eliminate the inhibitor titer. However, this method is extremely expensive because 100 to 200 units Zkg of FVIII preparation is administered twice a day every day, or 25 units Zkg is administered every other day for a long period of time. With bleeding tendency and anaphylaxis There are many issues such as risks, and only patients with relatively low inhibitors can be targeted.

Patent Publication No. 28381666 describes a method for suppressing inhibitor production using an immune complex comprising an FVIII antigen component and an FVIII inhibitor component obtained mainly from the plasma of a patient. Disclosed are pharmaceutical compositions and methods. However, the anti-FVIII inhibitor antibody used is basically prepared from human plasma components such as patients, and requires a great deal of labor to prepare the components, and it is difficult to maintain uniform quality. is there. In addition, it has been reported that a large number of immune complexes are present in the plasma of patients with inhibitors. Therefore, consideration should be given to enhanced deposition of the complexes in the kidney and side effects.

On the other hand, an anti-idiotypic antibody of an inhibitor antibody using a peptide of a variable region of the humanized monoclonal antibody and antibody fragment molecule of the present invention, in particular, a peptide of the complementarity determining region (CDR) or a polymer carrier modified with the peptide. If production is to be induced, it may be possible to use a similar approach to normal vaccination;

It is considered that a patient having one inhibitor having the same specificity and reactivity as the humanized monoclonal antibody and antibody fragment molecule of the present invention has the same idiotype.

In addition, the inventors have found that, among the disclosed antibody variable regions, in particular, the CDR3 region of the Η chain and the CDR3 region of the L chain are important for stabilizing the binding between the inhibitor antibody and FVIII. . Therefore, if immunization of patients with these CDR peptides could induce the production of anti-idiotype antibodies, it would be possible to suppress the action of inhibitor antibodies in blood. In addition, this method is intended to induce the production of anti-idiotypic antibodies, particularly against the complementarity-determining regions of the inhibitor antibody.However, the generated anti-idiotypic antibodies may also induce apoptosis of inhibitor antibody-producing B cells. It has been suggested that it is possible to provide a safe treatment method that is extremely specific and does not involve a risk such as an increase in bleeding tendency. As described above, the humanized monoclonal antibody of the present invention can neutralize the coagulation activity of blood coagulation factor VIII, and can be used as a drug for preventing and treating thrombosis. Wear. In particular, the humanized monoclonal antibody of the present invention does not recognize the blood coagulation factor VIII-von Willebrand factor complex and recognizes only blood coagulation factor VIII that is not bound to von Willebrand factor. Therefore, the antithrombotic agent has an extremely long half-life in blood and is expected to have an excellent effect of hardly causing bleeding, and its effect can be monitored by APTT measurement or the like.

The antibody can also be used to diagnose activated factor VIII in the blood.

Furthermore, by using the humanized monoclonal antibody of the present invention, it becomes possible to isolate a peptide that is an antigen peptide and to isolate an anti-idiotypic antibody in plasma. The resulting peptides and anti-idiotypic antibodies are expected to be effective for the treatment of hemophilia patients who have produced inhibitor antibodies due to their mechanism of neutralization or tolerance.

Furthermore, the anti-idiotype of the inhibitor antibody can be obtained by using a peptide at the variable site of the humanized monoclonal antibody and antibody fragment molecule of the present invention, in particular, a peptide of the complementarity determining region (CDR) or a polymer carrier modified with the peptide. A novel tolerogenic drug that induces antibody production is provided.

Hereinafter, the present invention will be described in more detail with reference to Examples, but these Examples do not limit the scope of the present invention.

<< Example 1: Construction of phage library from hemophilia patient >>

The construction of the phage library was prepared by referring to the method reported by J. D. Marks et al. (J. ol. Biol., 222: 581-597, 1991).

Lymphocytes were separated from 28 ml of peripheral blood of a patient having an anti-FVIII inhibitor antibody using Ficoll, washed thoroughly with PBS, and treated with IS0GEN (Nippon Gene) to prepare total RNA. Divide this total RNA into three, and use strand primers specific for the constant regions of the human IgG, / c and λ chains, and use the first strand cDNA synthesis kit.

(Pharmacia bio tec) to prepare each cDNA. Using this cDNA as a template, primers specific to each gene family were used in combination with VH and JH and Vκ and Jκ and Jλ in the same manner as reported by Marks et al. The antibody V region gene was amplified by the polymerase chain reaction (PCR) method.

Further, VH, VK, and VH are assembled using linker DNA. The single-stranded scFv DNA was prepared by ligation by one PCR method. scFvDNA was further subjected to NotI and SfiI restriction enzyme sites using PCR, electrophoresed on an agarose gel, and purified. The purified scFv01 ^ is digested with restriction enzymes 3 fi I (Takara) and Not I (Takara), and then phagemid pCANTAB5E

(pharmacia). pCANTAB5E to which sc Fv DNA was bound

Each of VH-V / c and VH-V was introduced into O. faecalis TG1 by electroporation. From the number of transformed TG1, VH—V / c and VH—νλ were evaluated to have a diversity of 1.03 × 10 ⁷ and 4.85 × 10 ⁶ clones, respectively. A phage antibody was expressed from the transformed TG1 using Ml3KO7 helper phage, and a patient-derived scFv-displaying phage library was prepared.

<< Example 2: Screening >>

10 units / mL blood coagulation factor VIII (cross-linked) dissolved in screening buffer (4% skim milk, 0.5% serum albumin, 50 jug / mL mouse IgG, 0.1% Tween 20, TBS) Eight M) was dissolved in 500 μL of screening buffer and 0.5 μg / mL biotinylated anticoagulant factor VIII monoclonal antibody FVIII: C14-182 (mouse, factor VIII light chain recognition, Or 500 μL of FVIII: C14-282 (mouse, recognition of heavy chain 82 domains) in a plastic test tube (FALC0N2058), mixed and reacted at room temperature for 30 minutes. To this was added 1 mL of a human-derived antibody-derived antibody phage library (single-chain antibody-displayed phage solution), reacted at room temperature for 1 hour, and further reacted at 4 ° C overnight.

Add 100 μL of avidin-bound magnetic particles (Perseptive) treated with 2% skim milk-0.05% Tween20-TBS to the above-mentioned biotinylated anti-FVIII monoclonal antibody: ¥ 111 mixed solution 1111 and gently mix for 15 minutes »J did. The magnetic particles were collected using a magnetic rack, washed eight times with 0.05% Tween20-TBS, and then twice with Tris buffer. The washed magnetic particles were suspended by adding 1 mL of a glycine buffer and left at room temperature for 10 minutes to elute single-chain antibody-displayed phages. The pH of the eluted phage was adjusted by adding 500 μL of 1M Tris (hydroxymethyl) aminome thane-HC1 (pH 7.5), and then 5 mL of a culture solution of E. coli TGI in logarithmic growth phase was added. TG 1 was infected by gentle shaking at 37 ° C for 1 hour. After infection The TGI was centrifuged at 3000 × g for 5 minutes, the supernatant was removed, suspended in 200 // L 2XYT medium, seeded on a SOBAG plate, and cultured in an incubator at 30 ° C. The resulting colonies were suspended and recovered using a scraper (Coastor) after adding an appropriate amount of 2XYT medium. This TGI 500 // L was inoculated in 5 OmL of 2XYTAG medium and rescued using helper phage to prepare a phage library after screening. Screening was performed a total of three times for each of the phage primaries VH-VK and VH-νλ derived from hemophilia patients. After the third screening, a clone was arbitrarily extracted from the SOB AG plate, and the expression of scFv was confirmed, the specificity was confirmed by FVIII sandwich ELISA, and the nucleotide sequence was analyzed.

<< Example 3: Expression and recovery of sc Fv >>

Soluble scFV was expressed using Escherichia coli HB2151, recovered from the Escherichia coli periplasmic fraction, and crudely purified. If further purification was required, affinity purification was performed using RPAS Purification Module (Pharmcia Biotech).

The purity of the purified scFV protein was confirmed by SDS-polyacrylamide gel electrophoresis and Western blotting targeting the C-terminal E-Tag epitope of scFV protein. A Protein Assay kit (BI0-RAD) was used to determine the protein concentration of the scFV protein purified product.

<< Example 4: Screening FVIII EL ISA >>

The ELISA for screening the isolated clones was performed as follows.

Two types of anti-FVIII mouse monoclonal antibodies with different antigenic determinants of FVIII: C14-182 and FVIII: C14-282 recognizing two domains of FVIII light chain recognition were immobilized on ELISA plate and used for screening. . Put 5 μg / mL anti-FVIII monoclonal antibody FVIII: C14-182 or FVIII: C14-282 into a 100 L / well ELISA plate (AXIS0RP module (Nunc)) and use a plate sealer (Sanko Junyaku). The cells were sealed and left at room temperature or at 4 ° C. for one day to immobilize the antibodies. After washing three times with TBS, 1% BSA and TBS were placed in a 300 μL / well ELISA plate, and allowed to stand at room temperature for 1 hour to perform blocking. 10 units / mL of blood coagulation factor VIII factor solution (Cross-Eight Ml 000 (S-Red Cross)) at 100 / i L / well ELISA The plate was placed in an A plate, sealed with a plate sealer, and allowed to stand at 37 ° C for 2 hours. The FVIII solution was discarded, and the plate was washed 5 times with an ELISA plate washing solution. Then, a sample solution containing scFv or scFV-displaying phage was added at 100 / XL / well, and allowed to react at room temperature. After the sample solution was discarded and washed 5 times with the washing solution, 100 μL / well of a horseradish-derived peroxidase-labeled secondary antibody was added thereto, and reacted at 37 ° C. for 1 hour. Discard the reaction solution, wash 5 times with the ELISA plate washing solution, add 100 / iL / well of a chromogenic substrate solution (TMBZ-hydrogen peroxide), shield from light, and develop color at room temperature to 37 ° C for 5 to 10 minutes. I let it. After 1 N sulfuric acid was added at 100 / L / well to stop the color reaction, the absorbance at 450 nm was measured with a Molecular Device multiplate reader SPECTRA MAX. All 99 clones evaluated were evaluated by FVIII sandwich ELI SA

It was confirmed and confirmed to be FVI11-specific.

<< Example 5 _: Sequence analysis of clone >>

The isolated region around the scFV gene of Knee Knee was amplified by PCR, and the resulting PCR product was digested with 3 to 5 types of restriction enzymes, such as PstI and KpnI, and subjected to agarose electrophoresis. Colonies were classified based on the band pattern. As a result, 13 clones having the complete scFV gene were identified. The DNA sequences of VH and VL of these clones were determined using Dye terminator cycle sequencing FS Ready Reaction kit (Applied Biosystems).

<< Example 6: Evaluation of isolated human anticoagulant factor VIII single-chain antibody >> As a result of performing an anticoagulant activity test with FVIII ELISA using purified scFV,

Seven types were confirmed to specifically bind to FVIII. Three of them were found to inhibit the coagulation activity of FVIII. The three clones YK3.3.38, ΥΚ3.3.40 and ΥΚ3.3.50 were examined in detail.

Anti-FVIII monoclonal antibody FVIII: C14-182 or FVIII: C14-282 Immobilized plate (MAXIS0RP module (Nunc)) adjusted to 0.001 to 10 units / mL F

VIII solution (Cross-Eight Ml 000 (Japan Red Cross)) was placed in a 100 μL / well ELISA plate, sealed with a plate sealer, and allowed to stand at 37 ° C. for 2 hours. After the FVIII solution was removed by suction and washed five times with the washing solution, sc / FV solution was added at 100 / ZL / well, and the reaction was carried out at room temperature overnight. Aspirate the sample solution and wash 5 times with washing solution. 100 μL / well of a horseradish-derived peroxidase-labeled anti-E tag antibody was added and reacted at 37 ° C. for 1 hour. After the sample solution was removed by suction and washed five times with the washing solution, 100 µL / well of a chromogenic substrate solution (TMBZ-hydrogen peroxide) was added, light was shielded, and the color was developed at room temperature to 37 ° C for 10 minutes. After 100 N of 1 N sulfuric acid was added to stop the color reaction, the absorbance at 450 nm was measured using a Molecular Device multiplate reader SPECTRA MAX. FIG. 1 shows the results when YK3.3.38 scFv was used. It was shown that FVIII can be detected and measured with high sensitivity of 0.01 unit / ml or more. Since the blood concentration of FVIII was reported to be more than 0.01 unit / ml even under the condition of strong bleeding tendency, this measurement system has sufficient sensitivity for monitoring activated FVIII in blood. Was.

<< Example 7: Anticoagulant activity test >>

The evaluation of the isolated human anticoagulant factor VIII single-chain antibody was performed using the partially activated thromboplastin time (APTT) using Test Team FVIII Kit (Daiichi Pure Chemicals) and FVIII-deficient plasma (DADE). ).

The reaction of the Test Team FVIII kit was as described in the attached instruction manual, Procedure A, but the scale was reduced to 14 so that it could be measured with a 96-well microphone plate.

Partial activation thromboplastin time (APTT) was measured using a Fibrintimer (Behring) according to the following literature method: National Committee for Clinical Laboratory Standards. Collection, transport ana processing oi blood specimens for coagulation testing and performance of coagulation assays. 2nd Edition. Approved Guideline. NCCLS Publication H21-A2.

Villanova, PA. 1991 .; Sirridge, M.S .; Shannon, R. Laboratory Evaluation of Hemostasis and Thrombosis, 3rd Ed., Philadelphia: Lea and Febinger, 1983: 130-133.

In the antigen-antibody reaction, an equal amount of the antibody sample diluent and 1 unit of Zml FVIII solution (Cross M) were mixed and reacted at 37 ° C for 2 hours or more. Then, the test team FVIII kit or partially activated thromboplastin time (APTT) was measured. Fig. 2 shows the measurement results obtained with the test team FVIII kit. All clones were shown to strongly inhibit FVIII activity at a concentration of 10 ng / ml or more. The same results were obtained with the partially activated dangling thromboplastin time (APTT). << Example 8: Examination of influence in the presence of von Willebrand factor >>

In the antigen-antibody reaction of the above example, both FVIII containing little vWF (Crossate M, manufactured by the Red Cross) and purified FVIII containing multimeric vWF (Confatato F, manufactured by Chemistry and Serological Therapy Research Institute) were used. The effect of the existence of vWF was compared and examined. Figure 3 shows the results obtained by using YK3.3.38 by measuring partially activated thromboplastin time (APTT). A commercially available inhibitor patient plasma (GedrgeKingMedical, Inc. lot. GK1833-929J2) was used for comparison.

These studies revealed that the anti-FVIII antibody clones YK3.3.38, YK3.3.40, and YK3.3.50 of the present invention did not inactivate FVIII bound to vWF, but did inactivate FVIII present alone. Was.

Claims

The scope of the claims

1. A gene fragment encoding a VH chain of a human anti-FVIII antibody having an activity (inhibitor activity) of inhibiting the coagulation activity of human blood coagulation factor VIII (hereinafter sometimes referred to as FVIII).

2. The human anti-FVIII antibody is an antibody that recognizes and does not recognize the FVIII-von Pinolebrand factor (hereinafter sometimes referred to as vWF) complex and recognizes only FVIII not bound to vWF. The gene fragment according to 1.

3. The gene fragment according to claim 1, wherein the complementarity determining region (CDR 1-3) of the VH chain is the following amino acid sequence.

CDR 1: Glu Leu Serlie His SEQ ID NO: 13>

CDR 3: Gly Val Ala Ser Asp Asp Asp Ala Phe Glu lie SEQ ID NO: 15>

4. The gene fragment according to any one of claims 1 to 3, wherein the VH chain comprises a base sequence encoding an amino acid sequence selected from SEQ ID NOs: 2, 6, or 10.

5. A gene fragment encoding a VL chain of a human anti-FVI11 antibody having an activity of inhibiting the coagulation activity of human FVIII (inhibitor activity).

6. The human anti-FVIII antibody according to claim 5, which is an antibody that does not recognize the FVIII-von Willebrand factor (hereinafter sometimes referred to as vWF) complex and recognizes only FVIII that is not bound to vWF. Gene fragment.

7. The gene fragment according to claim 5, wherein the complementarity determining regions (CDRs 1 to 3) of the VL chain have the following amino acid sequence.

CDR1: Arg Ala Ser Gin Serlie Xal Xa2 Tyr Leu Asn (Xal: Ser or Thr; Xa2: Ser or Arg) SEQ ID NO: 16>

CDR 2: Ala Ala Ser Ser Leu Gin Ser SEQ ID NO: 17>

8. The gene fragment according to claim 5, wherein the VL chain comprises a base sequence encoding an amino acid sequence selected from SEQ ID NOs: 4, 8 and 12 in the sequence listing.

9. A single-chain Fv (hereinafter referred to as sc Fv) obtained by binding the VH chain gene according to any one of claims 1 to 4 and the VL chain gene according to any one of claims 5 to 8 There is also) gene.

10. The VH chain gene according to any one of Claims 1 to 4 and the VL chain gene according to any one of Claims 5 to 8 are used as a human antibody CH chain gene and a human antibody, respectively.

A gene fragment encoding a human anti-FVI11 antibody that binds to a C light chain gene.

1 1. The VH chain gene and Z according to any one of claims 1 to 4, or the VL chain gene according to any one of claims 5 to 8, respectively, can be used for human antibody CH chain gene or a part thereof and Antibody A gene fragment encoding a human anti-FVIII antibody fragment which binds to a CL chain gene or a part thereof.

12. The gene fragment according to claim 11, wherein the antibody fragment is selected from Fab, Fab ', or F (ab,) ₂ .

13. A humanized anti-FVIII antibody fragment obtained by binding the single-chain Fv gene according to claim 9 to a human antibody CH chain gene or a part thereof, or a human antibody CL chain gene or a part thereof. Gene fragment to encode.

14. A human anti-FVIII antibody or a human anti-FVIII antibody fragment which is obtained by incorporating the gene fragment according to any one of claims 1 to 13 into an expression vector and expressing the same by a gene recombination method.

15. A prophylactic / therapeutic agent for thrombosis using the human anti-FVIII antibody or humanized antibody fragment according to claim 14.

16. An activated FVIII diagnostic agent using the human anti-FVIII antibody or human FVIII antibody fragment according to claim 14.

17. An scFV display phage library created using scFV DNA prepared by random combination of VH chain gene and VL chain gene of immunoglobulin derived from lymphocytes of hemophilia A patient A method for screening an anti-FVIII-scFv display phage clone, which comprises reacting FVIII immobilized on a solid phase via a solid phase to isolate a scFv clone capable of binding to FVIII.

18. Make sure that the anti-FVIII monoclonal antibody is a mouse monoclonal antibody. The screen Jung method according to claim 17.

19. The screening method according to claim 17 or 18, wherein the anti-FVIII monoclonal antibody is an antibody that recognizes and recognizes two regions of FVIII or an activated VIII L chain.

20. The screening method according to any one of claims 17 to 19, wherein the anti-FVIII monoclonal antibody is a biotinylated antibody, and the solid phase is avidin-immobilized magnetic particles.